In semiconductor manufacturing, a plating tool uses a negatively charged anode (usually a copper anode) to plate a positively charged (cathode) silicon wafer. The anode provides a source of replenishing metal ions. At the cathode, the metal ions are reduced to metal and deposited on the cathode surface. Sulfuric acid and a plating solution flows through a chamber around the anode and is used to dissolve a metal (copper) plate. As fluid (plating solution) flows past the anode, it becomes enriched with metal ions. The plating cell generally includes an anode (copper) held in anode holder, and a diffuser assembly.
Conventionally, numerous fluid and electrical connections are required for the plating tool. Such connections generally utilize O-rings, washers and fitting nuts to ensure a sealed connection. Some of these parts require complex machining. The fittings must be electrically conductive and compatible with the plating solution. Titanium is commonly used, as it meets these criteria. As a result, the fittings are a large percentage of the cost of the device.
The anode is replaced often, requiring removal of the plating cell from the tool, and significant disassembly. Simplified and reduced numbers of fluid and electrical connections would simplify this process.
It is therefore an object of the present invention to provide improved fluid and electrical connectology for a plating tool.
The problems of the prior art have been overcome by the present invention, which provides a plating cell base design that utilizes a single connection that provides both fluid communication and electrical communication to the cell. The design eliminates many of the components previously necessary to effectuate fluid and electrical seals. With fewer connections, material cost is reduced, reliability is enhanced, and downtime is reduced.